Structure I00090219+01692 · Silver Bow County, MT

I 90 over Int Nissler

Carries I 90 over Int Nissler, 1.2m W Rocker.

Overall conditionFair

Set by its lowest-rated component: Deck and Substructure at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructuresets the rating6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT293 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 6/9 · sets the rating

293 ft end to end, longest span 97 ft: about 4 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built196858 years old
Length293.0 ft89.3 m
Daily traffic7,361counted 2023
Last inspectedJanuary 2024every 24 months

Location

StateMontana
CountySilver Bow
Location1.2m W Rocker
CarriesI 90
CrossesInt Nissler
Coordinates46.00832, -112.63812

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length293.0 ft (89.3 m)
Max Span97.4 ft (29.7 m)
Deck Width40.7 ft (12.4 m)
Deck Area1107.3 sq m
Main Spans4
Year Built1968

Traffic

Avg Daily Traffic7,361 (2023)
Truck Traffic15%
Lanes On Bridge2
Lanes Under Bridge6

Inspection & Ownership

Last InspectionJanuary 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure NumberI00090219+01692

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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